Portable or mobile devices originally introduced as mobile phones or electronic agendas become more and more ubiquitous. As the processing power of their internal processors grows and equally the bandwidth for communication with stationary processors, such portable devices take on more and more the role of multi-purpose tools available to consumers and specialist users alike.
It has been recognized that portable devices can benefit from the presence of sensors capable of providing a chemical analysis of materials brought into contact or the vicinity of the device. Whilst there are many possible applications for such sensors, it suffices to consider for example the analysis of air surrounding the portable device. Such an analysis can be useful for multiple purposes such as testing for hazardous gases, breath analysis for general medical purposes or driving fitness, and the like.
However, the chemical analysis of an air sample is recognized as a very difficult problem. This problem is compounded by the limited size of portable equipment, which in turn limits the size and number of the sensors which can be housed inside the device. Furthermore, if the device is designed as a general purpose device the possible number of different samples taken and the conditions under which the sampling is performed become virtually unlimited.
One possible solution to this problem is seen in using a combination of several sensors to measure physical parameters which are known to have a relevance for the sampling or testing. For example, the chemical sensor can be made up of several chemical sensors or arrays of chemical sensors with different, i.e. orthogonal, sensitivities that can be used to improve the capacity of the sensor to distinguish between different compounds. Other physical sensors are temperature and humidity sensors, which under certain conditions can be used to improve the chemical measurement.
However, as stated above the assembly of a plurality of physical sensors is difficult to implement in the often limited space afforded to sensors in portable devices. Further limits are posed by the energy consumption of such a plurality of sensors, which in a general purpose portable device have to compete for the limited amount of battery power with other functions often considered more fundamental such as telecommunication, imaging, video and music capture and reproduction.
In view of the above problems it is seen as an object of the invention to provide a portable electronic device and related methods for increasing the accuracy of a chemical sensing process as performed by a sensor located within its housing.